.DELTA..sup.1 -Tetrahydrocannabinol [THC], depicted in Formula I under alternate numbering systems, is the major psychoactive constituent of marijuana. ##STR1## In addition to mood-altering effects, THC has been reported to exhibit other activities, some of which may have therapeutic value. The potential therapeutic value of THC has led to a search for related compounds which, while devoid of psychoactive effects, retain the activities of potential medicinal value.
Previous work with .DELTA..sup.6 -Tetrahydrocannabinol [(3R,4R) 6a,7,10,10a-tetrahydro-6,6,9-trimethyl-3-pentyl-6H-dibenzo[b,d]pyran-1-ol, hereinafter referred to as .DELTA..sup.6 -THC], has indicated that derivatives of this compound may prove clinically useful. The 7-carboxy derivative of .DELTA..sup.6 -THC [.DELTA..sup.6 -THC-7-oic acid] has been reported to be a non-psychoactive, potent antagonist to endogenous platelet activating factor and, thus, a useful treatment for PAF-induced disorders, such as asthma, systemic anaphylaxis, and septic shock. (U.S. Pat. No. 4,973,603, issued Nov. 27, 1990 to Sumner Burstein). Another derivative, (3S,4S)-7-hydroxy-.DELTA..sup.6 -THC-1,1-dimethylheptyl, has been reported to possess analgesic and anti-emetic activities. (U.S. Pat. No. 4,876,276).